Beolab 5 - Four Questionable Technologies

Hdomke,

To clarify my statement about Beolab 5 imaging-
I used a double negative:

I was stating tha the imaging problem (like the congestion problem) may be due to poor performance by the speaker or may be due to set-up. I just don't know. That's why I said an in-home demo in a room large enough to get the speakers away from the walls will be essential.

I'm happy that B&O accomodated you. The sound I heard was poor enough in certain, specific ways that I am inclined to believe that (at least) part of the problem HAD to be the set-up, otherwise those rave reviews would be hard for me to understand.

OTOH, Shadome heard a pair that seemed to be set up in a better (though perhaps still less than ideal) way and heard some of the same issues. I am eager to hear about your demo and i look forward to your post.

To sum up:

1) I wouldn't dismiss this speaker until I heard it set up properly
2) The demo I heard was pretty terrible for a speaker in this $ range.

I hope that clarifies.

Marty

the BeoLab5 radiates full power throughout the mid-to-treble range towards the side (unlike a conventional box speaker whose output sharply attenuates to the sides)

Not all conventional box speakers have narrow dispersion ( no side radiation ) - good speakers will have wide dispersion at least as wide as far as it matters (to be affected by side wall reflection to listener).

"Not all conventional box speakers have narrow dispersion ( no side radiation ) - good speakers will have wide dispersion at least as wide as far as it matters (to be affected by side wall reflection to listener)."

Shadorne,

I think that the reason for our disagreement is due to the way that we're each using the term "wide dispersion". I am not disputing that there are conventional front-radiating speakers with wide dispersion, but it is a fact that all conventional front-radiating speaker will become increasingly directional as you go up in frequency.

To illustrate my point, please take a look at the polar response graphs in this website.

http://www.mcsquared.com/speakers1.htm

Notice how the bass is virtually omnidirectional even for a front-firing speaker, but the midrange and treble gets increasingly directional. This happens because the wavelength of sound becomes shorter and shorter as you go up in frequency, hence the sound waves cannot "wrap" around the loudspeaker. Yes, some front-firing designs manage to achieve exceptionally wide dispersion through a narrow baffle configuration, but in the end there is no way to cheat the laws of physics and a front-firing speaking will never be able match the broadband off-axis output of a true omni-directional design. This is why an omni speaker will always be more susceptible to early reflections from nearby surfaces compared to a front-firing speaker (even when compared to a front-firing speaker that has exceptional dispersion), thus greater care in positioning is required.

In the end, my point is that you cannot apply the exact same method of speaker placement to both front-firing speakers and omni speakers. Placing a conventional speaker 3 feet from an untreated wall may have worked for you in the past, but this just isn't going be optimal for an omni speaker. When you switch to an omni speaker, the difference in its radiation pattern simply requires a change in your thinking.

Oxia,

I agree. I do not like omnidirectional or dipoles or forward and rear radiating panels or ribbon speakers for the very reasons you give about the reverberation they create. It creates ambience at the expense of imaging and soudstage and clarity. BTW: I have soffit mounted my mains - so I have eliminated the nasty rear radiation in the omnidirectional mid bass (with its inherent quarter wavelength cancelations that the listener hears as a "comb filter", altering certain notes as it affects harmonic balance in the lower midrange) The improvement from soffit mount versus non soffit mount is significant - image and tangibility of sounds improve further and make for a very solid soundstage but most people would never bother to go to this much trouble.

I just noticed I was asked questions on your post.

1. I question that review, only because that particular mag never ever in my experience recommends something that expensive, and it is clear the author had a prior thing going on the design of the Beolab. But I question it mainly because they never,ever never recommend anything that expensive in that magazine, but then again, it may be that good. So I don't disregard it, it just strikes me as very strange.

2. I have no idea about the reviewer, except I generally believe most reviewers try to do a good job and he seemed fairly technically knowledgeable during the review.

And I LIKE omnis, because you are not nailed to a sweetspot ...and no matter what anybody says, the omnis I have measured have better dispersion than any box speaker I have measured, by a fair amount. It is a tradeoff if you are not sitting in an exact spot, which, I agree, will tend to be the absolute best measured place if a room is done right. The question is, do you want a solitary hobby or one you share... do you want to sit in more than one spot? If so, omni, if no... box.

Cheers!
Chris